1. Field of the Invention
The invention relates to an adjustable vehicle seat.
2. Description of the Related Art
An adjustable vehicle seat, in particular a motor vehicle seat, has an inclinable seat part and an inclinable backrest mounted to the seat part. The seat part is mounted pivotably in bearings at the front and rear adjacent to remote sides of the seat part. The bearings are mounted pivotably in the vehicle floor or rails for longitudinally adjusting the vehicle seat. The front or rear bearings can be adjusted by adjusting means so that the spacing of the pivot axes of the respective bearing and the inclination of the seat part change.
Vehicle seats, such as those of passenger vehicles, have diverse adjustment options. For example, the height, longitudinal position, inclination and/or depth of the seat and the inclination of the backrest can be adjusted.
Vehicle seats with a “parallelogram-type height adjustment” can adjust the inclination and the height of the seat part at the same time by designing the bearings of the height adjustment means as links.
EP 0 445 528 A2 discloses an adjustable vehicle seat of the type mentioned above. The vehicle seat has a seat support with the function of the seat part described above. The seat part is mounted pivotably in the links. A posterior and thigh rest which is mounted pivotably in the seat supports adjacent to the backrest and is intended for the seat user. Toggle levers are mounted pivotably in the seat rails of the vehicle seat at positions in front of the seat supports, with respect to the customary direction of travel. The toggle levers are mounted at their ends facing away from the seat rails in a pivotable manner in the posterior and thigh rest in front of the seat supports. Thus an independent adjustment of the inclination of the posterior and thigh rest with respect to the seat supports. A backrest is mounted in the rear end of the seat supports in the region of the rear ends thereof. In this case, an articulated fitting for adjusting the angle of the backrest in relation to the seat supports can be provided.
The known vehicle seat disadvantageously has a structurally highly complicated design with the diverse links for adjusting the inclination of the seat supports and of the posterior and thigh rest. Furthermore, an adjustment of the inclination of the seat supports causes a corresponding adjustment of the inclination of the backrest, but no compensation for the adjustment of the backrest to the effect that the backrest has an unchanged inclination with respect to the floor of the vehicle so that the vehicle seat user can substantially retain the leaning inclination of his back when the position of the posterior and thigh rest changes.
Adjustable vehicle seats for motor vehicles also are known from EP 0 594 526 A1, DE 197 54 962 C1, DE 101 46 144 A1 and DE 42 28 849 C1.
It is an object of the present invention to develop a structurally and kinematically simple adjustable vehicle seat of the type mentioned above where an adjustment of the inclination of the seat part leaves the angle of inclination of the backrest relative to the vehicle floor substantially unchanged.